The present invention relates to lamp bulbs for a Christmas tree light set, and relates more particularly to such a lamp bulb which has two filaments connected between two lead wires thereof at different elevations.
A regular lamp bulb 10' for Christmas tree light, as shown in FIGS. 1 and 2, comprises a mother bulb 26', a daughter bulb 27' inside the mother bulb, a first lead-in wire 21', a second lead-in wire 22', a mica disc 25' fastened to the first lead-in wire 21' and the second lead-in wire 22' inside the daughter bulb 27', an exhaust bead 20' fastened to the first lead-in wire 21' and the second lead-in wire 22' inside the daughter bulb 27' and below the mica disc 25', and a filament 23' connected between the alloy tip of the first lead-in wire 21' and the magnesium-coated tip of the second lead-in wire 22' inside the daughter bulb 27' and spaced from the mica plate 25' at one side opposite to the exhaust bead 20'. Because this structure of lamp bulb has only one filament disposed inside the daughter bulb, it is less brightness when turned on.